1. Chapter 9
Moving to Design
Part 1

2. Learning Objectives Explain the major components and levels of design
Describe each design phase activity
Describe common deployment environments and matching application architectures

3. Overview
This chapter
Completes the transition from analysis to design
Discusses issues related to design of new system
Describes all design phase activities
Describes network and architecture design
Analysis focuses on what system should do— business requirements
Design is oriented toward how system will be built —defining structural components

4. Understanding the Elements of Design
Design is process of describing, organizing, and structuring system components at architectural design level and detailed design level
Focused on preparing for construction
Like developing blueprints
Three questions
What components require systems design?
What are inputs to and outputs of design process?
How is systems design done?

5. Information Systems Architecture
Information Systems Architecture is the process of making the key choices that are essential to the development of an information system. Architecture includes:
Guiding Principles:
Approaches/philosophies
“Logical” representations of a system
Hardware/Operating System
Computing model: client/server vs traditional vs Web-based
Tools and technologies
It is key, when making these choices that they are:
Requirements driven
Take into consideration operational, technical and financial feasibility
Made within an architectural framework

6. There are a lot of Drivers of Architecture
Architecture Drivers
There are a lot of Drivers of Architecture
Business
Plan
Corporate
Politics
System
Qualities
Current
Systems
End User
Requirements
Emerging
Technologies
Architecture

7. Architecture to Design to Implementation
Looking at the Work of Developing a System as a set of Choices,
Architecture can be Described as Highest Level Choices
Removal of Choices
Business Strategy
Line of Code / Process Step
Employee / Computer
Architecture
Design
Implementation

8. How is Architecture Different from Design?
Its not – Architecture can be considered ‘high-level’ design
Architecture includes those aspects of the design that are essential to the information system
Architecture Example:
Users must be able to self-serve (guiding principle)
“We will use a “hub and spoke” design where data will be placed in a central data warehouse, then be propagated to one or more data marts. (approach)
We will normalize data in the central warehouse and use a dimensional design in the data marts (approach)
We will use Oracle 8i as our DBMS (technical architecture)

9. Architecture vs. Detail Design
Not Architecture:
The Order subject area will be composed of the following tables: order_fact, customer_dim, product_dim and time_dim
The customer_dim table will have the following attributes…….

10. Components Requiring Systems Design

11. Analysis Objectives to Design Objectives

12. Moving from Analysis to Design
Converts functional models from analysis into models that represent the solution
Focused on technical issues
Requires less user involvement than analysis
Design may use structured or OO approaches
Database can be relational, OO, or hybrid
User interface issues

13. Traditional Structured and Object-Oriented Models (Figure 9-3)

14. SDLC Phases with Design Phase Activities